This invention relates to transmission ratio selector mechanisms for use with transmission stages of the type including two coupling members both of which are slidable either side of their respective neutral position to couple a selected one of a respective pair of gears to a respective shaft and both of which must be engaged to provide drive through the transmission stage.
GB-B-2055162 discloses an example of such a transmission stage which is used as an input stage into a multi-ratio tractor transmission. In this example one of the coupling members in the input stage selects either of a pair transmission ranges and the other coupling member selects the forward/reverse drive direction of the transmission.